Originally Posted by
PeteHski
My Charge 3 also tries to tell me I've got a max HR of around 140 when my accurate Polar HRM is reading 170+
The Fitbit simply isn't reliable when exercising. The only time it reads accurately is when I'm just pottering around. I've had reasonable results with sleep monitoring as it happens, but totally useless for exercise HRM.
My FitBit WAS reading my heart rate correctly at 140 while riding (I checked it by manually taking my pulse). I did some other activities at the FB went up to 160+
I attribute my 'low' rates by saying that I have thick Scandinavian blood. Like pumping a higher viscosity fluid. I have high blood pressure, but low rate. It baffles the Doc somewhat, so I use my high-viscosity fluid analogy Then he 'got it'...